Topic 5 - Organic Chermistry Flashcards
(48 cards)
What is a homologous series?
A group of compounds with the same general formula so have the same elements & similar molecular formula, giving them similar chemical properties & react in a similar way
How do the physical properties of the homologous series change as they increase in size?
The boiling points increase as size increases (e.g. in fractional distillation)
What is the general formula for an alkane?
CnH2n+2
What is the formula for: methane? ethane? propane? butane?
CH4
C2H6
C3H8
C4H10
What is the difference between alkanes and alkenes?
Alkenes have at least one double bond in their chain of carbon atoms
What is the general formula for an alkene?
CnH2n
What is the formula for:
ethene?
propene?
butene?
C2H4
C3H6
C4H8
What is the general formula of an alcohol?
CnH2n+1OH
What is the formula for: methanol? ethanol? propanol? butanol?
CH3OH
C2H5OH
C3H7OH
C4H9OH
What is the functional group of an alcohol?
-OH
What is the functional groups of carboxylic acid?
-COOH
What is the general formula of carboxylic acid?
CnH2n+1COOH
What is the formula for: methanoic acid? ethanoic acid? propanoic acid? butanoic acid?
HCOOH
CH3COOH
C2H5COOH
C3H7COOH
What is the symbol equation for the fermentation of glucose?
C6H12O6 –yeast–> 2C2H5OH + 2CO2
How would you make a dilute solution of ethanol from glucose/other carbohydrates?
- Fermentation
- Mix yeast (contains an enzyme) + solution of a carbohydrate in clean container. Seal + leave in warm place
- Keep between 30 & 40˚C as temp than happens quicker (low = slower, fast = denaturing)
- Keep in anaerobic conditions as O2 converts ethanol to ethanoic acid
- When conc at 10-20% fermentation stops as yeast killed by alcohol
- Yeast falls to bottom, can collect ethanol from top
After the fermentation of carbohydrates into alcohol, how can the alcohol be made more concentrated?
Distilling
What is the process through which alcohol can be made more concentrated?
- Fractional distillation
- Ethanol has lower boiling point than water so when fermentation mixture is heated, ethanol evaporates + vapour rises up fractionating column, while water stays liquid
- Liebig condenser used to condense ethanol vapour by cooling it so concentrated ethanol can be collected in a separate flask
What are the advantages and disadvantages of fermentation?
+Uses renewable source so won’t run out
- Poor quality of ethanol
- So expensive to concentrate + purify ethanol
How is ethanol produced industrially?
- Ethene (C2H4) made by cracking crude oil fractions
- Ethene reacts with steam to make ethanol
What is the advantage of the industrial production of ethanol?
- Relatively cheap as ethane’s fairly cheap + not much wasted
- Made in large chemical plant so made continuously + quickly. Product = high quality + needs little further processing
What is the disadvantage of the industrial production of ethanol?
-Ethane’s produced from crude oil which isn’t renewable so ethanol will become v. expensive
What is the word equation for the reaction of ethene with water?
ethene + water (steam) –> ethanol
What effects does alcohol have on the body?
- Less inhibited so socialise + relax w/ each other
- Reduces activity of nervous system, increasing reaction times, impaired judgement, poor balance/coordination, unconsciousness, coma
- In excess = dehydration, damaging brain cells causing drop in brain function leading to long term memory loss. Also liver damage = liver disease
What effects does alcohol have on society?
- Loutish behaviour + violence
- Addiction, alcoholism, leading to family breakdowns, + alcoholics losing their jobs or becoming homeless
- Drunk = irresponsible sexual behaviour, increasing risk of catching STIs
- Drink driving = serious injury/death
- Economic costs: more people to deal w/ drunks
